Timosaponin AIII enhances CAR-T cell potency and prevents relapse through impairing CAR-Tregs
Chimeric antigen receptor (CAR)-T cell therapy has transformed treatment of relapsed/refractory DLBCL, yet resistance driven by regulatory T cells (Tregs) limits its efficacy. Here we identify Timosaponin AIII (TAIII), a clinical-stage natural product, as an effective modulator of CAR-T function that depletes CAR-Tregs while enhancing effector activity. Mechanistically, TAIII acts as an allosteric A2AR inhibitor by competing with cholesterol, suppressing CREB-dependent FoxP3 transcription and disrupting the A2AR-Treg axis. Ablation of A2AR or Tregs in vitro and in vivo abolishes TAIII activity, confirming specificity. Furthermore, TAIII reduces intratumoral Tregs, increases CD8⁺ T cells infiltration, and potentiates PD-1 blockade in solid tumor models. Importantly, TAIII promotes central memory T-cell formation and enhances CAR-T cytotoxic cytokine secretion. Combining or pretreating CAR-T cells with TAIII markedly improves antitumor efficacy and prevents late relapse across preclinical models. These findings establish TAIII as a combinatorial strategy to deplete CAR-Tregs, enhance CAR-T activity, and extend therapeutic durability.
Authors
- Rui Jin (ORCID: https://orcid.org/0000-0002-7946-3686)
- Ziyue Qi (ORCID: https://orcid.org/0009-0008-3075-589X)
- Aoli Wang (ORCID: https://orcid.org/0000-0002-2329-2865)
- Xiaosong Tang (ORCID: https://orcid.org/0000-0001-7898-7907)
- Xiuchun Li (ORCID: https://orcid.org/0000-0002-5604-9538)
- Shuang Qi (ORCID: https://orcid.org/0000-0002-0193-8813)
- Husheng Mei
- Mingqi Hou
- Xi Chen (ORCID: https://orcid.org/0000-0002-8523-3967)
- Bing Xiu
- Zhan Xu (ORCID: https://orcid.org/0009-0005-1975-0420)
- Rui Liang (ORCID: https://orcid.org/0009-0004-6748-5142)
- Yuanzhang Zhao (ORCID: https://orcid.org/0009-0003-3613-9469)
- Jun Long
- Aibin Liang
- Changlin Qian
- Wenchao Wang
- Qingsong Liu
- Jing Yang
- Jing Liu
- Guiming Li
- Ping Li
- Lejin Yan
- Dan Li
- Chen Hu
- Yongfei Chen
- Bin Li
- Beilei Wang
- Chao Wu
- Wenjun Zhang
Institutions
- Tongji University (CN)
- University of Science and Technology of China (CN)
- Anhui University (CN)
- Shanghai Jiao Tong University (CN)
- Renji Hospital (CN)
- Hefei Institutes of Physical Science (CN)
Publication Details
- Journal
- Nature Communications
- Published
- 2026-03-31
- DOI
- https://doi.org/10.1038/s41467-026-70867-5
- Citations
- 1
- Primary Topic
- CAR-T cell therapy research
- Type
- article
- Field-Weighted Citation Impact
- 14.16
Funders
- National Natural Science Foundation of China
- Youth Innovation Promotion Association of the Chinese Academy of Sciences
- Shanghai Jiao Tong University
- School of Medicine, Shanghai Jiao Tong University
- Fundamental Research Funds for the Central Universities
- Youth Innovation Promotion Association